We previously demonstrated that outcome of pediatric 11q23/MLL-rearranged AML depends on the translocation partner (TP). In this multicenter international study on 733 children with 11q23/MLL-rearranged AML, we further analyzed which additional cytogenetic aberrations (ACA) had prognostic significance. ACAs occurred in 344 (47%) of 733 and were associated with unfavorable outcome (5-year overall survival [OS] 47% vs 62%, P < .001). Trisomy 8, the most frequent specific ACA (n = 130/344, 38%), independently predicted favorable outcome within the ACAs group (OS 61% vs 39%, P = .003; Cox model for OS hazard ratio (HR) 0.54, P = .03), on the basis of reduced relapse rate (26% vs 49%, P < .001). Trisomy 19 (n = 37/344, 11%) independently predicted poor prognosis in ACAs cases, which was partly caused by refractory disease (remission rate 74% vs 89%, P = .04; OS 24% vs 50%, P < .001; HR 1.77, P = .01). Structural ACAs had independent adverse prognostic value for event-free survival (HR 1.36, P = .01). Complex karyotype, defined as ≥ 3 abnormalities, was present in 26% (n = 192/733) and showed worse outcome than those without complex karyotype (OS 45% vs 59%, P = .003) in univariate analysis only. In conclusion, like TP, specific ACAs have independent prognostic significance in pediatric 11q23/MLL-rearranged AML, and the mechanism underlying these prognostic differences should be studied.

doi.org/10.1182/blood-2010-12-328302, hdl.handle.net/1765/33392
Blood
Erasmus MC: University Medical Center Rotterdam

Coenen, E., Raimondi, S., Harbott, J., Zimmermann, M., Beverloo, B., Chang, M., Creutzig, U., Dworzak, M., Forestier, E., Gibson, B., Hasle, H., Harrison, C., Heerema, N., Kaspers, G., Leszl, A., Litvinko, N., Nigro, L., Morimoto, A., Perot, C., … van den Heuvel-Eibrink, M. (2011). Prognostic significance of additional cytogenetic aberrations in 733 de novo pediatric 11q23/MLL-rearranged AML patients: Results of an international study. Blood, 117(26), 7102–7111.https://doi.org/10.1182/blood-2010-12-328302